Sacha Baron Cohen’s films provoke such an intense physical reaction in me that I sometimes wonder if I might be allergic to them.

Brüno and Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan, are the worst: they make me laugh until my lungs ache and cringe until my stomach muscles cramp. The measure of a successful Hollywood comedy is normally how good it makes you feel; a successful Baron Cohen film causes acute discomfort.

As the creator of Ali G, Borat and Brüno, Baron Cohen has given us three of the most sublimely vulgar comic characters of the modern age. In two weeks, we will possibly have a fourth. His new film, The Dictator, arrives in cinemas later this month and centres on General Colonel Doctor Aladeen, a cheerful north African despot whose diplomatic visit to the USA goes horribly awry. In a typically Baron Cohen-esque flourish, it is a loose adaptation of Zabibah and the King, a novel by the late Iraqi ruler Saddam Hussein.

Setting aside his supporting roles in Hugo, Talladega Nights and Sweeney Todd, this will be Baron Cohen’s first conventional comedy, with both a script and a witting supporting cast, since 2002’s Ali G Indahouse. It will also be his first film to feature a character that he has not tested out on television first. It does, however, feature jokes about HIV, terrorism and violence against children, so should fit neatly alongside his other work.

To say he’s ploughing his own furrow is an understatement: Baron Cohen’s raucous comic grotesquerie has no obvious precedent in cinema. His voices owe something to Peter Sellers, his physicality to Jacques Tati and his gonzo documentary style to the TV satirists Chris Morris and Paul Kaye, but he goes much, much further than any of them.

He is often called a Jewish comedian, which is correct in the most literal sense: he was brought up in an observant, middle-class family in Hammersmith, west London, and his wife, the actress Isla Fisher, converted to Judaism before the birth of their first daughter, Olive, in 2007. (“I wouldn’t say I am a religious Jew,” he has told US public radio network NPR, “but I am proud of my Jewish identity and there are certain things I do and customs I keep.”)

His films, however, have almost nothing in common with any strand of Jewish humour. Baron Cohen’s sexually rapacious loons are the polar opposite of Woody Allen’s self-critical, romantically-impaired nebbishes. Unlike Alvy Singer, it’s hard to imagine Ali G even taking a metaphysics exam, let alone cheating by looking into the soul of the “batty boy” sitting next to him.

In fact, his characters are defined by their screaming unJewishness. Brüno’s stated ambition is to become “the biggest Austrian superstar since Adolf Hitler”, Borat has blamed Israel for everything from the 9/11 terrorist attacks to the extinction of the dinosaurs, and in a video released shortly before February’s Oscar ceremony, Aladeen railed against the machinations of the “Academy of Motion Picture Arts and Zionists”.

So if his comedy isn’t Jewish, what is it? Satire? A reaction against political correctness? His films have been called both of these things, but again, neither claim stands up. His characters – a wannabe gangster from the Home Counties, a perverted Kazakh, a gay Austrian fashionista and a bearded African tyrant – aren’t exactly relevant satirical targets. And as far as painting them as champions of free speech goes – well, if you ever want to argue that something is inoffensive “because Borat said it”, then best of luck with that.

In fact, his films are rooted in a far darker, stranger comic tradition, and it’s this that gives his work its primal, gut-wrenching kick. After reading history at Christ’s College, Cambridge, Baron Cohen studied for a year under the French clown Philippe Gaulier. In the 1960s, Gaulier and the celebrated mime Jacques Lecoq revived a long-forgotten style of comedy that thrived in the travelling fairs of medieval Europe: buffoonery.

Buffoons were social outcasts, often deranged or deformed, who turned to street performance to earn a crust. Clad in gaudy costumes, they drew enormous crowds with their filthy talk and bizarre voices, and by tormenting any members of the ruling classes or the clergy who should pass by. Audiences watched in a state of half-amusement, half-dread: nobody knew what a buffoon might say or do next. Being insulted by one of these pitiable creatures was an outrage; being complimented was perhaps even worse.

Baron Cohen was so impressed that he wrote the preface to Gaulier’s book on buffoonery, the aptly-titled Le Gégèneur: The Tormentor. “Imagine my excitement when I heard that, instead of attending one of the 'great’ British drama schools, where fencing, practising iambic pentameter and 'memory recollection’ of painful childhood experiences would be the staples of the course, there was a legendary teacher of theatre who was giving courses on how to be a professional idiot,” it begins.

He has been acting the buffoon ever since. Think of Ali G’s interview with Tony Benn, in which the Old Labour grandee railed against his suggestion that unions call strikes “cause they is lazy and wanna chill”, or Brüno’s trip to Lebanon, where he tells the stunned leader of the Al-Aqsa Martyrs’ Brigade that al-Qaeda are “so 2001”. Think, if you can stomach it, of Borat’s nude wrestling match that spills over into a mortgage brokers’ conference: a none-too-subtle reminder that beneath the surface, we are all naked, hairy, wobbling idiots.

That’s what makes Baron Cohen such an exhilarating comic force: his characters exist in that dangerous space between fact and fiction, where they can tap into our most primitive can’t-look-must-look instincts and make us painfully aware of our own absurdity. Whether The Dictator will be on a par with his earlier work remains to be seen. But if it makes me feel excruciatingly uncomfortable, it must be doing something right.